Mutans streptococci genetic strains in children with severe early childhood caries: follow-up study at one-year post-dental rehabilitation therapy

Abstract

BackgroundGenotypic strains of cariogenic mutans streptococci (MS) may vary in important virulence properties. In previous published studies, we identified 39 MS strains from pediatric patients undergoing full-mouth dental rehabilitation, including the removal and/or repair of carious lesions and application of antimicrobial rinse and fluoride varnish.ObjectivesThe objectives of this current 1-year follow-up study are to assess the variability of MS strains that occur at 1-year post-rehabilitation and characterize the xylitol-resistance properties of MS strains that predominate.MethodsPlaque from five children with severe early childhood caries was collected 1-year post-rehabilitation. MS isolates were subjected to arbitrarily primed-polymerase chain reaction (AP-PCR) for identification of genetic strains and in vitro xylitol-inhibition experiments. To more precisely define strain distributions within each patient, we isolated large numbers of isolates per patient.ResultsMS strains diminished from several strains pre-rehabilitation, to one dominant strain at 1-year post-rehabilitation, with several new emergent strains. The majority of the clinical MS strains, as well as the Streptococcus mutans laboratory strains ATCC 25175 and 35668, were predicted to undergo 50% inhibition with 2.48–5.58% xylitol, with some clinical MS strains being significantly more resistant in vitro.ConclusionsOur follow-up study using patients from the original cohort demonstrates that specific MS strains are dominant at 1-year post-dental rehabilitation. Most of the clinical MS strains are similar in xylitol resistance to the attenuated S. mutans ATCC control strains, with some strains being more resistant to xylitol in vitro.

Maturation of Oral Microbiota in Children with or without Dental Caries

“…For example, Actinomyces , Campylobacter , Leptotrichia , and Streptococcus genera have been reported in Swedish adolescents living in the same area as those in the present study (Johansson et al ., personal communication). Furthermore, Campylobacter [ 43 ], Granulicatella [ 44 ], Kingella [ 43 ], Leptotrichia [ 21 ], and Streptococcus (particularly Streptococcus sanguinis) [ 13 , 39 , 44 , 45 ] have been associated with caries-free teeth in pre-school, and schoolchildren. However, comparisons with other studies is hampered by the fact that they are performed in different socio-economic conditions, different stages of the disease and different ages.…”

Antibacterial Effect of Hydroalcoholic Extract ofPunica granatumLinn. Petal on Common Oral Microorganisms

“…Oral streptococci are the first isolated species to play a role in the formation of dental plaque and development of caries [ 5 – 7 ]. Measures taken to clinically inhibit plaque accumulation, namely, tooth brushing, dental flossing, and use of mouth rinses (as an adjunct), are highly effective for preventing the supragingival plaque and gingivitis and decreasing the number of microorganisms [ 8 ]. Chlorhexidine is among the most widely used antimicrobial mouthwashes.…”

Comparison of Oral Microbial Profiles between Children with Severe Early Childhood Caries and Caries-Free Children Using the Human Oral Microbe Identification Microarray

“…The Human Oral Microbe Identification Microarray (HOMIM), which targets approximately 300 predominant oral bacterial species that include cultivable and not-yet-cultivated phylotypes (HOMIM home page: http://mim.forsyth.org /), has recently been used to determine bacterial profiles and microbial diversity in the oral cavity and compare these between healthy individuals and those with oral diseases such as periodontitis [ 6 , 7 ]. In the present study, we used HOMIM with the aim of comparing the bacterial profiles in saliva and supragingival plaque samples between children with SECC and caries-free children to investigate the etiology of caries in the primary teeth.…”